5 Business level requirements

28.5003GPPManagement concept, architecture and requirements for mobile networks that include virtualized network functionsRelease 17Telecommunication managementTS

5.1 Requirements

5.1.1 General requirements

REQ-NFV-CON-1 Operator shall be able to manage mobile networks that include virtualized network functions and shall be able to identify whether the managed nodes are virtualized or not.

REQ-NFV-CON-2 The management of mobile networks that include virtualized network functions should reuse the 3GPP existing management solutions as much as possible.

REQ-NFV-CON-3 NM and EM in 3GPP management system managing the virtualized 3GPP entities shall be able to manage physical 3GPP entities also.

REQ-NFV-CON-4 3GPP management system shall support a capability allowing operators to manage mobile networks that include virtualized network functions with the assistance from NFV-MANO.

REQ-NFV-CON-5 The reference points between 3GPP management system and NFV-MANO shall support a capability allowing 3GPP management system to request information required for management from NFV-MANO.

REQ-NFV-CON-6 The performance of the 3GPP management system should be adequate to achieve the objective of 3GPP service time to market.

REQ-NFV-CON-7 The virtualized resources from NFVI, on which the VNF relies, should be collaboratively managed by 3GPP management system and NFV-MANO.

NOTE: Management of the virtualized resources from NFVI is NFV-MANO’s responsibility, and "collaboratively managed" refers to the need for NFV-MANO to take into account the requirements from 3GPP management system about the VNF’s virtualized resources during the VNF lifecycle management and deliver to 3GPP management system VNF performance data related to virtualized resources, VNF fault information related to virtualized resources and VNF instance information.

5.1.2 FM requirements

REQ-NFV_FM_SYS-CON-1 The Operator shall be able to manage and deal with the virtualized network function alarms and NFVI alarms, which are not related to virtualized network function, through 3GPP management system and NFV-MANO respectively.

REQ-NFV_FM_SYS-CON-2 3GPP management system shall be able to receive the virtualized network function alarm which includes the correlated virtualized resource fault information and process the alarm.

REQ-NFV_FM_SYS-CON-3 The virtualized network function alarm, which 3GPP management system acquired, shall include correct alarm type, alarm severity and possible cause information.

REQ-NFV_FM_SYS-CON-4 3GPP management system shall be able to request NFV-MANO to recover the virtualized network function when VNF automatic recovery is not enabled in NFV-MANO.

REQ-NFV_FM_SYS-CON-5 3GPP management system shall be able to receive the virtualized network function alarms when NFV-MANO performs VNF automatic recovery.

REQ-NFV_FM_SYS-CON-7 NFV-MANO shall support the subscription capability allowing 3GPP management system to subscribe to the VNF instance fault report related to virtualized resource(s) and virtualization-specific failures.

5.1.3 CM requirements

REQ-NFV_CM_SYS-CON-1 3GPP management system shall be able to manage both physical and virtualized 3GPP entities with corresponding managed objects and attributes.

REQ-NFV_CM_SYS-CON-2 3GPP management system shall be able to perform necessary virtualized 3GPP entity configuration due to the VNF lifecycle management operation from NFV-MANO.

REQ-NFV_CM_SYS-CON-3 3GPP management system shall be able to re-configure involved neighbour physical and virtualized 3GPP entities if needed due to one NS or VNF LCM operation.

REQ-NFV_CM_SYS-CON-4 In order to minimize 3GPP service disruption when a VNF instance is scaled, the scaling shall not modify the existing connections with other network entities.

REQ-NFV_CM_SYS-CON-5 3GPP management system shall be able to request NFV-MANO to modify non-application information and configuration about a VNF instance managed by NFV-MANO (supported by requirements Os-Ma-nfvo.NsLcm.019 and Os-Ma-nfvo.NsLcm.020 in [9], and Ve-Vnfm-em.VnfLcm.008 and Ve-Vnfm-em.VnfCm.001 in [10]).

REQ-NFV_CM_SYS-CON-6 3GPP management system shall be able to query NFV-MANO non-application information about a VNF instance managed by NFV-MANO (supported by requirement Os-Ma-nfvo.NsLcm.015 in [9] and Ve-Vnfm-em.VnfLcm.004 in [10]).

5.1.4 PM requirements

REQ-NFV_PM_SYS-CON-1 The key performance indicators which are defined for physical entities shall be applicable to virtualized entities in 3GPP core network.

REQ-NFV_PM_SYS-CON-2 3GPP management system shall support the performance measurements for virtualized 3GPP entity and 3GPP management system shall be informed of the performance measurement result of virtualized resources on which the virtualized 3GPP entity relies.

REQ-NFV_PM_SYS-CON-3 3GPP management system shall be able to request the VNF LCM operation towards NFV-MANO to mitigate the VNF performance bottleneck according to the results of the VNF performance measurements.

REQ-NFV_PM_SYS-CON-4 NFV-MANO shall be able to provide VNF PM data related to virtualized resource to 3GPP management system.

REQ-NFV_PM_SYS-CON-5 NFV-MANO shall support the subscription capability allowing 3GPP management system to subscribe to the VNF performance measurement report related to virtualized resource.

5.1.5 LCM requirements

REQ-NFV_LCM_SYS-CON-1 3GPP management system shall be able to request NFV-MANO to perform NS LCM operations (defined in ETSI GS NFV-IFA 013 [9]).

REQ-NFV_LCM_SYS-CON-2 3GPP management system shall be able to request NFV-MANO to perform NSD management operations (defined in ETSI GS NFV-IFA 013 [9]).

REQ-NFV_LCM_SYS-CON-3 3GPP management system shall be able to request NFV-MANO to perform VNF package/software management operations (defined in ETSI GS NFV-IFA 013 [9]).

REQ-NFV_LCM_SYS-CON-4 3GPP management system shall be able to request NFV-MANO to perform VNF LCM operations (defined in ETSI GS NFV-IFA 008 [10]).

REQ-NFV_LCM_SYS-CON-5 3GPP management system shall support the capability to receive NS lifecycle change notifications from NFV-MANO (defined in ETSI GS NFV-IFA 013 [9]).

REQ-NFV_LCM_SYS-CON-6 3GPP management system shall support the capability to receive the NSD management notifications from NFV-MANO (defined in ETSI GS NFV-IFA 013 [9]).

REQ-NFV_LCM_SYS-CON-7 3GPP management system shall be able to request updating the NS instance (defined in ETSI GS NFV-IFA 013 [9]).

REQ-NFV_LCM_SYS-CON-8 3GPP management system shall support the VNF package/software management notifications from NFV-MANO (defined in ETSI GS NFV-IFA 013 [9]).

REQ-NFV_LCM_SYS-CON-9 3GPP management system shall support the capability to receive the VNF LCM change notifications from NFV-MANO (defined in ETSI GS NFV-IFA 008 [10]).

REQ-NFV_LCM_SYS-CON-10 3GPP management system shall be able to request scaling a virtualized network function to NFV-MANO (defined in ETSI GS NFV-IFA 008 [10]).

REQ-NFV_LCM_SYS-CON-11 3GPP management system shall be able to request executing the VNF Healing of a virtualized network function to NFV-MANO.REQ-NFV_LCM_SYS-CON-12 3GPP management system shall have the authority to determine the termination of a VNF instance(s).

REQ-NFV_LCM_SYS-CON-13 NFV-MANO shall have the capability allowing 3GPP management system to enable/disable the auto-scaling towards the corresponding VNF instance(s).

REQ-NFV_LCM_SYS-CON-14 NFV-MANO shall support the subscription capability allowing 3GPP management system to subscribe to the NS lifecycle change notifications (defined in ETSI GS NFV-IFA 013 [9]).

REQ-NFV_LCM_SYS-CON-15 NFV-MANO shall support the subscription capability allowing 3GPP management system to subscribe to the VNF lifecycle change notifications (defined in ETSI GS NFV-IFA 008 [10]).

REQ-NFV_LCM_SYS-CON-16 NFV-MANO shall have the capability allowing 3GPP management system to provide the affinity and anti-affinity information in the NSD.

REQ-NFV_LCM_SYS-CON-17 Operator shall be able to instantiate and manage multiple NS created using the same NSD but with specific parameterization (location, capacity, addresses).

5.2 Actor roles

See detailed actors and roles for each use case in clause 5.4.

5.3 Telecommunications resources

See detailed telecommunications resources for each use case in clause 5.4.

5.4 High-level use cases

5.4.1 FM use cases

5.4.1.1 Use case of VNF Healing triggered by 3GPP management system

Note: In the context of this use case, VNF Healing [2] refers to corrective actions performed by the NFV-MANO to recover a VNF which fails to perform as expected, and it concerns the actions for which the NFV-MANO is responsible, e.g. corrective action(s) toward virtualised resources, instantiation of VNFC, configuration of VNF non-application specific parameters, etc.

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

To execute VNF Healing for a virtualized network function.

Actors and Roles

3GPP management system requests to execute the VNF Healing.

Telecom resources

3GPP management system.

NFV-MANO.

VNF.

Assumptions

3GPP management system is subscribed to VNF lifecycle change notifications from the NFV-MANO.

Pre-conditions

The subject VNF instance is not being healed at the moment.

Begins when

A faulty virtualization-specific aspect of the VNF has been notified to 3GPP management system.

Step 1 (M)

3GPP management system determines that VNF Healing of the VNF is needed.

Step 2 (M)

3GPP management system requests the NFV-MANO to execute the VNF Healing based on the information in the request.

Step 3 (M)

NFV-MANO notifies 3GPP management system about the end and the result of the VNF Healing execution.

Ends when

All the steps identified above are successfully completed.

Exceptions

The VNF Healing procedure in step 2 fails.

Post-conditions

The faulty virtualization-specific aspect of the VNF is recovered.

Traceability

REQ-NFV_LCM_SYS-CON-11

5.4.1.2 Use case of virtualization-specific aspect failure detection and notification by NFV-MANO

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

To notify the 3GPP management system of a virtualization-specific failure of a virtualized network functions.

Actors and Roles

3GPP management system receives the fault report.

NFV-MANO notifies about VNF-related virtualization faults.

Telecom resources

3GPP management system.

NFV-MANO.

VNF.

Assumptions

3GPP management system is subscribed to VNF-related virtualization-specific fault reports from the NFV-MANO.

Pre-conditions

N/A

Begins when

A virtualization-specific fault affecting the VNF is notified to NFV-MANO.

Step 1 (M)

NFV-MANO creates VNF-related virtualization fault report about the faulty virtualization-specific aspect.

Step 2 (M)

NFV-MANO sends the VNF-related virtualization fault report to the 3GPP management system.

Ends when

All the steps identified above are successfully completed.

Exceptions

Post-conditions

The 3GPP management system is notified about the virtualization-specific failure of the subject VNF.

Traceability

REQ-NFV_FM_SYS-CON-7

5.4.1.3 Use case of alarms correlation by 3GPP management system

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

To correlate VNF alarms in a mobile network that includes virtualized network functions.

Actors and Roles

3GPP management system correlates VNF alarms.

Telecom resources

NFV-MANO

VNF

NFVI

Assumptions

3GPP management system has the alarm correlation function.

3GPP management system is subscribed to VNF-related virtualized resource fault reports from the NFV-MANO.

The virtualized resource failure affects the corresponding VNF.

Pre-conditions

Begins when

NFV-MANO detects the virtualized resource fault affecting the VNF.

Step 1 (M)

NFV-MANO creates VNF fault report related to virtualized resource and sends it to the 3GPP management system.

Step 2 (M)

3GPP management system receives the VNF fault report related to virtualized resource. 3GPP management system also receives VNF application alarm(s) of a faulty NE.

Step 3 (M)

3GPP management system implements alarm correlation based on the virtualized resource alarm(s) from NFV-MANO and VNF application alarm(s) from NE.

Step 4 (M)

3GPP management system generates the final VNF application fault report including the above correlated alarm(s).

Ends when

Ends when all mandatory steps identified above are successfully completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post-conditions

3GPP management system will process the alarm(s) based on the final fault report.

Traceability

REQ-NFV_FM_SYS-CON-2, REQ-NFV_FM_SYS-CON-7

5.4.2 CM use cases

Editor’s note: The following UCs (i.e. 5.4.2.1, 5.4.2.2, 5.4.2.3, 5.4.2.4) will be revisited when the relationship between MO and VNF instance is clear.

5.4.2.1 Use case of adding a MO related to a VNF

Use Case Stage

Evolution / Specification

<<Uses>>

Related use

Goal

To add a MO related to a VNF.

Actors and Roles

3GPP management system.

Telecom resources

3GPP management system.

VNF.

Assumptions

Pre conditions

N/A

Begins when

Operator has decided to add a MO related to the VNF.

Step 1 (M)

3GPP management system creates the MO related to the VNF.

Note: the MO creation operation here means Basic CM IRP.

Ends when

Ends when all mandatory steps identified above are successfully completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post Conditions

The MO is available for 3GPP management system.

Traceability

REQ-NFV_CM_SYS-CON-2

5.4.2.2 Use case of associating the MO with a certain VNF instance

Use Case Stage

Evolution / Specification

<<Uses>>

Related use

Goal

To associate the MO with a certain VNF instance.

Actors and Roles

3GPP management system.

Telecom resources

3GPP management system.

VNF.

Assumptions

Pre conditions

3GPP management system has known the VNF instance identifier.

Begins when

Operator has decided to associate the MO with a certain VNF instance.

Step 1 (M)

3GPP management system associates the MO with a certain VNF instance.

Note: The associating operation may happen during the process of creation of MO or after it.

Ends when

Ends when all mandatory steps identified above are successfully completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post Conditions

The MO is associated with The VNF instance. And the MO can be managed by 3GPP management system.

Traceability

REQ-NFV_CM_SYS-CON-2

5.4.2.3 Use case of configuring the VNF by 3GPP management system

Use Case Stage

Evolution / Specification

<<Uses>>

Related use

Goal

To configure the VNF with MO attributes.

Actors and Roles

3GPP management system.

Telecom resources

3GPP management system.

VNF.

Assumptions

Pre conditions

3GPP management system has added a MO related to the VNF.

Begins when

Operator has decided to configure the VNF.

Step 1 (M)

3GPP management system configures the VNF with MO attributes.

Ends when

Ends when all mandatory steps identified above are successfully completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post Conditions

The VNF has been configured by 3GPP management system.

Traceability

REQ-NFV_CM_SYS-CON-2

5.4.2.4 Use case of removing the MO of a VNF from managed nodes

Use Case Stage

Evolution / Specification

<<Uses>>

Related use

Goal

To remove the MO of a VNF from managed nodes.

Actors and Roles

3GPP management system.

Telecom resources

3GPP management system.

VNF.

Assumptions

Pre conditions

3GPP services provided by the VNF instance have been released.

NFV-MANO has already terminated the VNF instance.

Begins when

Operator has decided to remove the MO of the VNF instance from managed nodes.

Step 1 (M)

3GPP management system removes the MO of the VNF instance.

Ends when

Ends when all mandatory steps identified above are successfully completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post Conditions

The MO of the VNF instance has been removed from managed nodes.

Traceability

REQ-NFV_CM_SYS-CON-2

5.4.2.5 Modify non-application information and configuration of a VNF instance managed by NFV-MANO

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

To modify by 3GPP management system non-application information and configuration of a subject VNF instance. Such an information and configuration is managed by NFV-MANO (see clause 9.4.2 in ETSI GS NFV-IFA 008 [10]); for instance, VNF instance name and meta data.

Actors and Roles

3GPP management system requests the modification of VNF instance information and/or configuration.

Telecom resources

3GPP management system.

NFV-MANO

Assumptions

N/A

Pre-conditions

N/A

Begins when

3GPP management system determines to modify certain non-application information and/or configuration held by NFV-MANO of a subject VNF instance.

Step 1 (M)

3GPP management system sends a request to NFV-MANO to modify the non-application information and/or configuration about the subject VNF instance (see related interface requirements in clause 5.2.1.1 in ETSI GS NFV-IFA 008 [10] and in clause 5.3.2 in ETSI GS NFV-IFA 013 [9]).

Step 2 (M)

NFV-MANO modifies the requested information and/or configuration about the subject VNF instance.

Ends when

Ends when all steps identified above are completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post-conditions

The non-application information and/or configuration of the subject VNF instance managed by NFV-MANO instance has been modified.

Traceability

REQ-NFV_CM_SYS-CON-5

5.4.2.6 Retrieve non-application information of a VNF instance managed by NFV-MANO

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

To retrieve by 3GPP management system from NFV-MANO non-application information of a subject VNF instance. Such information about a subject VNF instance is information managed by NFV-MANO (see clause 9.4.2 in ETSI GS NFV-IFA 008 [10]).

Actors and Roles

3GPP management system queries the VNF instance information.

Telecom resources

3GPP management system.

NFV-MANO

Assumptions

N/A

Pre-conditions

N/A

Begins when

3GPP management system determines to retrieve certain information about a subject VNF instance that is managed by NFV-MANO.

Step 1 (M)

3GPP management system sends a request to NFV-MANO querying the needed non-application information about the subject VNF instance (see related interface requirements in clause 5.2.1.1 in ETSI GS NFV-IFA 008 [10] and in clause 5.3.2 in ETSI GS NFV-IFA 013 [9]).

Step 2 (M)

NFV-MANO returns to 3GPP management system the information requested about the subject VNF instance.

Ends when

Ends when all steps identified above are completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post-conditions

3GPP management system has the non-application information about the subject VNF instance managed by NFV-MANO.

Traceability

REQ-NFV_CM_SYS-CON-6

5.4.3 PM use cases

5.4.3.1 Use case of mitigating the VNF performance bottleneck

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

To mitigate the VNF performance bottleneck.

Actors and Roles

3GPP management system.

Telecom resources

NFV-MANO

VNF

Assumptions

3GPP management system is set up to collect VNF performance measurements and NFV-MANO is set up to collect VNF performance measurements related to virtualized resource.

Pre-conditions

VNF application threshold crossing trigger and VNF-related virtualized resource threshold crossing trigger have been set up by corresponding system(s) (i.e. 3GPP management system or NFV-MANO system).

Begins when

The VNF performance measurement report(s), VNF performance measurement report(s) related to virtualized resource or the thresholds crossing alarm(s) are generated.

Step 1 (M)

3GPP management system receives the VNF performance measurement report(s), VNF performance measurement report(s) related to virtualized resource or the thresholds crossing alarm(s).

Step 2 (M)

3GPP management system decides to optimize the VNF performance and mitigate the VNF performance bottleneck.

Step 3 (M)

3GPP management system requests VNF LCM operation (e.g. expansion) towards NFV-MANO.

Ends when

NFV-MANO executes the VNF LCM operation.

Exceptions

One of the steps identified above fails.

Post-conditions

The VNF performance bottleneck has been mitigated after the VNF LCM operation.

Traceability

REQ-NFV_PM_SYS-CON-3

5.4.3.2 Use case for collection of VNF PM data related to virtualized resource from NFV-MANO

Use Case Stage

Evolution / Specification

<<Uses>>

Related use

Goal

3GPP management system gets the VNF PM data related to virtualized resource.

Actors and Roles

3GPP management system

Telecom resources

3GPP management system

NFV-MANO

Assumptions

NFV-MANO is set up to collect VNF-related virtualized resource performance measurements and generates the report of VNF PM data related to virtualized resource.

Pre-conditions

The collection mechanism for VNF PM data related to virtualized resource has been established both at 3GPP management system and NFV-MANO.

Begins when

3GPP management system needs the VNF PM data which are related to virtualized resource and sets the PM job for them. And VNF PM data related to virtualized resource is generatedby NFV-MANO.

Step 1 (M)

NFV-MANO provides the VNF PM data related to virtualized resource to 3GPP manamement system.

Step 2 (M)

3GPP management system receives the VNF PM data related to virtualized resource.

Ends when

Ends when all mandatory steps identified above are successfully completed.

Exceptions

None.

Post-conditions

3GPP management system has the performance data desired.

Traceability

REQ-NFV_PM_SYS-CON-2, REQ-NFV_PM_SYS-CON-4

5.4.4 LCM use cases

5.4.4.1 Use case of NS instance Deployment

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

To deploy a NS instance in a mobile network that includes virtualized network functions

Actors and Roles

3GPP management system (NM part).

Telecom resources

NFV-MANO.

Assumptions

Existing VNF instance(s) could be used by the new NS instance.

Any NSD may be reused for instantiating multiple NS instances.

3GPP management system is subscribed to receive NS lifecycle change notifications.

Pre-conditions

The NSD to be used for the NS instantiation has been on-boarded on NFV-MANO.

Begins when

3GPP management system determines that a new NS instance is to be instantiated.

Step 1 (M)

3GPP management system determines the type and capacity of a NS instance, and sets NS instantiation request with proper parameters.

Step 2 (M)

3GPP management system sends NS instantiation request to NFV-MANO.

Step 3 (M)

NFV-MANO instantiates the NS instance based on request from 3GPP management system.

Ends when

3GPP management system receives notification from NFV-MANO that a new NS instance is instantiated.

Exceptions

One of the steps identified above fails.

Post-conditions

A new NS instance is ready for service.

Traceability

REQ-NFV_LCM_SYS-CON-1, REQ-NFV_LCM_SYS-CON-5, REQ-NFV_LCM_SYS-CON-17

5.4.4.2 Use case of updating an NS instance to a different NSD version

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

The network operator through 3GPP management system can decide when and has the capacity to update the NS instance (created based on an NSD of certain version) to correspond to a different NSD version.

Actors and Roles

3GPP management system.

Telecom resources

NFV-MANO

Assumptions

Pre-conditions

The information, to update an existing NS instance, to correspond to a different NSD version exists.

The different NSD version has been on-boarded on NFV-MANO.

Begins when

3GPP management system needs to update an existing NS instance (created based on an NSD of certain version) to correspond to the different NSD version.

Step 1 (M)

3GPP management system requests to NFV-MANO to update the NS instance to correspond to the different NSD version, instructing NFV-MANO not to synchronize automatically the NS instance to the different NSD version.

Step 2 (M)

NFV-MANO executes the NS update operation and acknowledges to 3GPP management system the successful update of the NS instance to correspond to the different NSD version.

Step 3 (M)

3GPP management system requests to NFV-MANO to update the NS instance based on the different NSD version.

Step 4 (M)

NFV-MANO executes the NS update operation and acknowledges to 3GPP management system the successful NS instance update.

Ends when

Ends when all steps identified above are completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post-conditions

The NS instance has been updated to correspond to the different NSD version.

Traceability

REQ-NFV_LCM_SYS-CON-1, REQ-NFV_LCM_SYS-CON-7

5.4.4.3 Use cases of NE deployment in the context of NFV

5.4.4.3.1 Use case of NE deployment in the scenario of Managed Object(s) creation is after the VNF instantiation

Use Case Stage

Evolution/Specification

<<Uses>>
Related use

Goal

To deploy a NE in a mobile network that includes virtualized network functions

Actors and Roles

3GPP management system (NM, EM) creates and configures Managed Object(s) for the corresponding VNF instance.
NFV-MANO system instantiates VNF instance according to the request from 3GPP management system.

Telecom resources

3GPP management system
NFV-MANO system

Assumptions

3GPP management system and NFV-MANO system are in operational status.

Pre-conditions

Operator has decided the type and capacity of the NE to be deployed.

Begins when

Operator decides to deploy a new NE.

Step 1 (M)

3GPP management system sends the VNF instantiation request to NFV-MANO system.

Step 2 (M)

NFV-MANO system instantiates the VNF instance.

Step 3 (M)

3GPP management system receives the result of VNF instantiation from NFV-MANO system.

Step 4 (M)

3GPP management system creates Managed Object(s) for the instantiated VNF instance when needed.

Step 5 (M)

3GPP management system configures the VNF instance with Managed Object attributes when needed.

Ends when

Ends when all mandatory steps identified above are successfully completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post-conditions

The new NE is deployed and ready for providing service.

Traceability

TBD

5.4.4.4 Use case for notifications about VNF lifecycle changes

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

To monitor by 3GPP management system of lifecycle changes on VNF instances.

Actors and Roles

3GPP management system subscribes to and receives VNF lifecycle change notifications.

Telecom resources

3GPP management system.

NFV-MANO system.

VNF.

Assumptions

Pre-conditions

NFV-MANO system is running.

Begins when

3GPP management system determines to monitor VNF lifecycle changes on a managed VNF instance.

Step 1 (M)

3GPP management system requests a subscription to NFV-MANO system to receive VNF lifecycle change notifications regarding a managed VNF instance.

Step 2 (M)

NFV-MANO system creates a subscription and acknowledges the subscription to 3GPP management system.

Step 3 (M)

When managed VNF instance has a lifecycle change, NFV-MANO system creates and sends VNF lifecycle change notification including information to identify the VNF instance subject to lifecycle change, the type of procedure, and whether it is the start or end of the procedure.

Ends when

3GPP management system unsubscribes to VNF lifecycle change notifications regarding the managed VNF instance.

Exceptions

Post-conditions

The 3GPP management system has information about VNF lifecycle changes of the managed VNF instance.

Traceability

REQ-NFV_LCM_SYS-CON-9, REQ-NFV_LCM_SYS-CON-15

Note: VNF lifecycle change notifications are supported by NFV-MANO system [2].

5.4.4.5 Use case of VNF instance scaling through operation request by 3GPP management system

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

To expand/contract a VNF instance by scaling the VNF instance.

Actors and Roles

3GPP management system detects the need for scaling and sends the VNF scaling request.

Telecom resources

3GPP management system.

NFV-MANO system.

VNF.

NFVI.

Assumptions

3GPP management system is subscribed to VNF lifecycle change notifications from the NFV-MANO system.

Pre-conditions

The subject VNF instance is not being scaled at the moment. VNFM (part of NFV-MANO system) does not have any auto-scaling scripts or the policy for auto-scaling is not in use or active.

Note: Determining whether "the subject VNF instance is not being scaled" can be done through the lifecycle change notification as described in clause 5.4.4.4 of TS 28.500. Determining whether "there is no auto-scaling scripts or policy for auto-scaling is not used or active" can be done by sending a query request for the subject VNF instance from the 3GPP management system to the NFV-MANO system as described in clause 6.4.7 of TS 28.510 [11].

"Use case for notifications about VNF lifecycle changes" (see clause 5.4.4.4 of TS 28.500)

"Retrieve VNF instance information from VNFM by EM" (see clause 6.4.7 in TS 28.510 [11])

Begins when

3GPP management system detected the need to scale and have determined the scaling action (expand/contract).

Step 1 (M)

3GPP management system sends to NFV-MANO system a request to expand/contract the managed VNF instance.

Step 2 (M)

NFV-MANO system executes the scaling of the VNF instance.

Step 3 (M)

NFV-MANO system notifies 3GPP management system about the end of the VNF scaling execution.

Ends when

All the steps identified above are successfully completed.

Exceptions

Post-conditions

The VNF instance has been scaled (expansion/contraction).

Traceability

REQ-NFV_LCM_SYS-CON-4, REQ-NFV_LCM_SYS-CON-9, REQ-NFV_LCM_SYS-CON-10

5.4.4.6 Use case of enabling/disabling the auto-scaling of the corresponding VNF instance(s)

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

According to the management requirement, operators need to enable/disable the auto-scaling of a VNF instance(s).

Actors and Roles

3GPP management system requests the enabling/disabling the auto-scaling of the corresponding VNF instance(s) for an NE.

Telecom resources

NFV-MANO, VNF

Assumptions

The auto-scaling, which means automatic procedure controlled and executed by NFV-MANO to scale the capacity of a VNF instance.

Pre-conditions

Begins when

The operator decides to enable/disable the auto-scaling of the corresponding VNF instance(s) for an NE.

Step 1 (M)

3GPP management system requests NFV-MANO to enable/disable the auto-scaling of the corresponding VNF instance(s) for the subject NE.

Step 2 (M)

NFV-MANO enables/disables the auto-scaling function towards the specific VNF instance(s).

Ends when

Ends when all steps identified above are completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post-conditions

The auto-scaling of the corresponding VNF instance(s) for an NE is enabled/disabled.

Traceability

REQ-NFV_LCM_SYS-CON-13

5.4.4.7 Determination on the termination of the corresponding VNF instance(s)

Use case stage

Evolution/Specification

<<Uses>>
Related use

Goal

The operator determines to terminate a VNF instance(s) based on the operator’s needs or the pre-configuration policy.

Actors and Roles

3GPP management system requests the termination of the corresponding VNF instance(s) for an NE.

Telecom resources

NFV-MANO, VNF

Assumptions

The operator makes the decision to terminate the corresponding VNF instance(s) for an NE.

Pre-conditions

Begins when

3GPP management system completes the preparation for the VNF termination.

Step 1 (M)

3GPP management system requests NFV-MANO to terminate the corresponding VNF instance(s).

Step 2 (M)

NFV-MANO completes the termination operation towards the specific VNF instance(s).

Ends when

Ends when all steps identified above are completed or when an exception occurs.

Exceptions

One of the steps identified above fails.

Post-conditions

Traceability

REQ-NFV_LCM_SYS-CON-12